JPS6232035A - Preparation of composite container - Google Patents

Abstract

PURPOSE:To make it possible to prepare a composite container in a low manufacturing defective rate, by contracting and deforming a thin-walled inner container having an appearance shape corresponding to the interior of a container main body by evacuating said inner container to insert the same in the container main body and subsequently restoring the shape of the inner container to constitute the inner container in the container main body. CONSTITUTION:A cylindrical parison 2A plasticized under heating is closed in a pair of molds 4 having cavities 5 constituted so as to correspond to the internal shape of a container main body 1 and a pressurized fluid is blown in the parison 2A from a blow nozzle 7 and the parison 2A is expanded so as to coincide with the shape of the cavities 5 to perform blow molding to obtain a thin-walled inner container 2B having an appearance shape corresponding to the container main body 1. Subsequently, a nozzle 8 is inserted in the inner container 2B from a mouth part holder 6 so as to reach the vicinity of the bottom part of the inner container 2B and the air in the inner container 2B is sucked to obtain an inner container 2C of which the volume is contracted and the shape is deformed. Subsequently, the inner container 2C of the contracted and deformed stage is inserted in the container main body 1 from the mouth part thereof and a fluid such as air is introduced into the inner container 2C from the nozzle 8 and the inner container 2C is expanded to restore an inner container 2 to obtain a composite container.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a composite container for storing foods, industrial chemicals, etc., which has a plastic inner container inside a container main body such as metal. .

[Conventional technology]

2. Description of the Related Art Composite containers are conventionally known in which a plastic inner container is constructed inside a container main body such as metal.

The following techniques are known as methods for manufacturing composite containers.

Conventional technology (^): A method in which a plastic inner container is installed inside a cylindrical metal container, and then the opening and bottom members of the container are attached. (For example, December 2, 1970
(Page 829 of the New Packaging Handbook, published by the Japan Productivity Center on May 0) Conventional technology (B): After placing a heated and softened plastic material inside the main body of the container, the above plastic material is placed inside the main body of the container. A method in which the main body of the container and the inner container made of plastic are joined together during blow molding. (For example, Utility Model Application No. 11, No. 185534/1983) [Problems to be Solved by the Present Invention] In the prior art (8), when the inner container is installed inside the container main body, the opening of the container main body This has the disadvantage that the process of caulking or gluing the members or the bottom member is complicated.

In conventional technology (B), when the heated plasticized plastic material is placed in the container main body, the plastic material is welded or comes into contact with the mouth of the container main body before blow molding. It has the disadvantage that it is not blow molded and has a high manufacturing defect rate.

[Means for solving problems]

The present invention solves the above-mentioned drawbacks, and eliminates the need to attach the opening member and the bottom member, which constitute a part of the container main body, in post-processing in order to install the inner container inside the container main body.
Another object of the present invention is to provide a method for manufacturing a composite container with a low manufacturing defect rate.

The above object of the present invention is achieved by installing the inner container, which has been previously formed into a three-dimensional shape, in a reduced and deformed state in the container body, and then restoring the inner container. More specific means of the present invention include a step of manufacturing a thin inner container having an external shape corresponding to the inside of the main container by blow molding a soft thermoplastic; a step of reducing and deforming the inner container by reducing the pressure; a step of inserting the inner container in the reduced and deformed state into the interior of the container main body from the mouth of the container main body; and the contents of the inserted reduced and deformed state. A method for manufacturing a composite container comprising the steps of introducing a fluid into the interior of the container to restore the shape of the inner container and configuring the inner container inside the main body of the container.

Regarding.

In the present invention, the inner container is Shore D (ASTM-02
240) is 50 or less, such as low-density polyethylene, ethylene-vinyl acetate copolymer, flexible polyvinyl chloride, and other thermoplastics with elastomeric properties, and the wall thickness can be reduced by a slight internal vacuum. For example, the average wall thickness of the body is set to be 2 fins or less, so that the volume is reduced and the shape is deformed. Furthermore, it is also possible to form a fold line or the like on the body of the inner container so that it can be easily deformed.

Further, it is preferable that the main body of the container has a rigid structure such as metal, hard plastic, glass, or hard paper.

[Effect]
1 The manufacturing method of the present invention includes a step of manufacturing an inner container,
It consists of a step of deforming the inner container, a step of installing the inner container inside the container main body, and a step of restoring the inner container.In the step of installing the inner container inside the container main body, the container, which has been formed into a three-dimensional shape in advance, is deformed. Therefore, there are no problems such as welding between the container body and the plastic that occur when plasticized plastic material is placed inside the container body, and the container body has a narrow mouth. However, the inner container can be easily installed inside the main body of the container.

〔Example〕

One embodiment of the present invention will be described below. Fig. 1 shows a composite container obtained by the manufacturing method of the present invention, where 1 is mainly made of a metal container, and 2 is made of soft thermoplastic plastic by blow molding. The inner container 3 is a cap having a thin wall structure.

First, to explain the manufacturing process of the inner container 2 according to FIGS. 2 and 3, a heated and plasticized cylindrical parison 2
A is a parimen 2A that is gripped by closing a pair of molds 4 having a cavity 5 configured to correspond to the internal shape of the container main body 1 and sealed in a mouth holder 6.
Blow pressure fluid into the inside from the blow nozzle 7,
The material is expanded into the shape of the cavity 5 and blow molded, and after cooling, the mold 5 is opened and the molded product is taken out.The thin-walled material i! has an external shape corresponding to the inside of the container main body 1 as shown in FIG.
Obtain S2B.

In the present invention, a known blow molding method can be used as a method for obtaining the inner container 2B, and the method is not particularly limited to the contents of the embodiments.

Next, the nozzle 8 is inserted into the inner container 2B from the mouth holder 6 to near the bottom of the inner container, and the gas inside the inner container 2B is sucked, so that the volume is reduced and the shape is deformed, as shown in FIG. An inner container 2C is obtained.

At this time, by inserting the nozzle 8 to the vicinity of the bottom of the container, the shape at the time of deformation can be made into a shape along the axis of the inner container 2A.

Next, as shown in FIG. 5, the compressed and deformed inner container 2C is inserted into the mouth of the container body 1, and fluid such as air is introduced into the inner container 2C from the nozzle 8 to close the inner container 2C.
The inner container 2 is expanded and restored, and a composite container as shown in FIG. 2 is obtained.

[Effects of the present invention]

In the manufacturing method of the present invention, since the inner container is installed inside the container main body, there is no need to attach the mouth member or the bottom member that constitutes a part of the container main body in post-processing, and the inner container and the container main body are stocked separately. By combining them, it is possible to manufacture them rationally and reduce the manufacturing defect rate. 〆

[Brief explanation of drawings]

Fig. 1 is a sectional view of a composite container obtained by the manufacturing method of the present invention, Fig. 2 is a sectional view of a mold showing the blow molding process of the inner container, and Fig. 3 is a sectional view of the inner container during blow molding. , FIG. 4 is a sectional view of the same as the above when it is reduced and deformed, and FIG. 5 is a sectional view showing a state in which the inner container is inserted into the main body of the container. l: Container main body 2: Inner container 3: Camping 4: Mold

Claims (1)

[Claims] A process for manufacturing a thin inner container having an external shape corresponding to the inside of a container body by blow molding a soft thermoplastic; a step of reducing and deforming the inner container, a step of inserting the inner container in the reduced and deformed state into the inside of the container main body from the mouth of the container main body, and introducing a fluid into the inside of the inserted inner container in the reduced and deformed state. A method for manufacturing a composite container, which comprises the steps of restoring the shape of the inner container and configuring the inner container inside the container main body.